the main thing is weather its still dry ie powder and the same colour as its always been .

hi tony i found some when i was clearing my mothers shed out when she passed away and it was fifteen years old then i have had it four years and still use it now and again as NP says if it dry it should be ok. good luck.

I always thought it lasted a season or a year at most. As per the above keeping it dry is key. I find it gets damp, even in storage. I do not actually think it improves rooting: a plant is going to root or not regardless which is possibly why Kennyboy has had it for 19 years...

well powder like cement , rooting powder,flower etc is a 100% dry so is unable to go off but it draws in dampness even some wear you think is dry and theres the key for keeping all powders for a long time . there benigne excuse my spelling while dry but need sealing to stay that way . that's the basic premmiss of mummification and why it works or kippers, dry fruit etc .it will work as well as it ever did as long as you keep it dry . that's why coffee kept in the jar stays good generally but can go hard in a coffee container you get with sugar and tea . the sugar is the same . the moisture from the spoon and the fact that there not sealed draws the moisture .

Hi, I'm with Botanic on this, I have never seen a use for it, and never used it, it seems to me that if someone has success rooting cuttings when they have used this, and had failures previously, they think it's marvellous, and swear by it, when in fact it's all down to taking the right type of cuttings, at the right time, and giving them the right conditions, Derek.